I remember when I first learned the word 花火... "Flower fire? How poetic!" (Likewise, a volcano is a 火山 (かざん), "fire mountain". Though maybe that one sounds more poetic to us than it does to the Japanese.)

I've always wondered if there was any connection between the word 花火 and the "fire flower" in Super Mario Bros., but as far as I can tell, that's a coincidence.